CSS Units Converter
Convert between CSS units instantly: px, rem, em, %, vw, vh, pt, cm, mm, in. Customize base font size and viewport dimensions for accurate conversions.
1
1rem
1
1em
100
100%
0.833333
0.833333vw
1.481481
1.481481vh
12
12pt
0.423333
0.423333cm
4.233333
4.233333mm
0.166667
0.166667in
Common Conversions
About This Tool
- Real-time conversion as you type — no button clicks needed
- Customizable base font size for accurate rem/em conversions
- Set viewport dimensions for precise vw/vh calculations
- Completely free with no registration required
Frequently Asked Questions
The CSS Units Converter lets you convert between all common CSS units in real-time: px, rem, em, %, vw, vh, pt, cm, mm, and in. Simply enter a value, select the source unit, and see all conversions instantly.
Rem and em are relative units based on the font size. 1rem equals the root font size (default 16px). 1em equals the parent element's font size. You can customize the base font size in settings for accurate conversions.
Viewport units are relative to the browser window size. 1vw equals 1% of the viewport width, and 1vh equals 1% of the viewport height. You can set custom viewport dimensions in the settings panel.
Yes, completely free with no registration. Convert between any CSS units with no limits — all processing happens in your browser.